Improvement in propellers



noBnarHUNTEa-or NEW Yoan, N.. Y.

Lette-.rs Patent No. 107,376, dated September 13, 1,87

IMPROVEMENT -IN PROPELLRS.

The Schedule referred to in these L etters Patent and makn'g part 0f thesame..

I, ROBERT:` HUNTER, of' thecity of `New York, doctor of medicine, haveinvented a new and useful Im# provement in Propellers, of which the'.followingr is a` specifica-tion.

-A'aturc all (Ng/'acts of the Invention.

i My invention relates chiefly to a class ofreeiproeatingpropellers,adapted,.by their construction, to act in a manner siinila-r to thetail. of a fish, and consists in constructing such propellcrs withsolidbladesof l ndia rubber, .tapering in thickness, and clanipedby ltheir thick edges between metallic bars in a vibrating tienne, ashereinafter described.

Description of the Accompanying Brewing. Figure 1 isa verticallongitudinal sect-ion ot' a' portion of' thc stern ot' a vessel, with myinvention applied.`

FigureQ represents a horizontal section of the. propcller at refr, iig.

General Description. Y A represents a parli of a ressels hull withinwhich, at or near the steril, or at the bow, o r in any other placewhere it may he desired to apply the propeller,

is a vertical casing or well, 15,'open to' the water-at betteln and tothe air at top. lhc said casing ex- 'tends upward well above thewater-line, and, prefera-r bly,np to the deck, so that,-though thewaterrises freely within the casing, it cannot thereby enter the vessel.

C is a shaft, so mounted as to turn or oscillatc freely within thecasing B.

Upon thelower part of this shaft. is mounted the propeller-frame, madepreferably ot' iron or steel, and consisting of two ormore dat bars, l)1),'piojecting horizontally or at rright angles to the shaft C, and a-number of bars, E, arranged in pairsparallel'withthe shaft C, andconnecting the bars D.

'The two bars E of each pair are set at the. necessary distancc asnnderto serve as a socket forthe reception'of the propelling-blades F, eachof which is made'of wedge shape, of India rubber, -and bolted by -itsthick edgebetween the two 'bars E.'

s The more flexible thin edge ofthe blade projects backward, so that, asthe shaft is vibrated, the blades will', by the resistance ofthe water,assume an oblique position on one side or the other, asindicated bydotted lines in lig. 2, and, by the Obliquity of the surfaces thuspresented, exert a powerful propellingr force nnder the vibration of thepropeller.

The bars are preferably taperediu thickness,

backward or toward the flexible blades, as shown in tig. 2. y Thevibratory movement may be imparted to the shaft C through thev medium ofan arm, G, within or in relation to which the shaft may be reversed, so.as to present thepropcller in either direction, and thus propel thevessel either 'forward or backward. The` arm G is to be actuated by apitman or connectingrod from a crank or reciprocating engine.

The shaft G is supported by a collar, H, secured by set-'screws I, orequivalent means, and removable when required, so that the shaft may bepassed downward Vthrough the casing B, and suspended by ac hain,

Lattachd to an eye-bolt, K, a second chain or line,

eitherpermanently attached or provided with a hook or'suitable grapple,being employed to take the'- propeller in board. It may thus beunshipped for examination, repair, or otlierpui'poses, withgreatpconvenience while the vessel is afloat, and afterward replaced bypassing -it over the side and drawing it np into its place, with equalfacility. Y

A propeller of the construction described 'may be ,arranged on ahorizontal shaft, if' preferred.

I am aware that propcllers 4have been made with tapering steel blades.`This, therefore, Ido not claim.

Mysolidrubbcr blades, usedin the manner described, possess severalimportant advantages. lhey weigh nothing in water, are'not'subjecttocorrosion, and, by having much-greater thickness at the base than ispracticable in steel bladesthey are found to assume, under theresistance of the' water, a better form for propulsion. y

The compressibility of thematerial is also of great practical value inthis connection, adapting it tol be clamped firmly between the metallicbars, without thedrilling that is necessary with steel blades'. Themetallic bars being clamped upon the 1ubber,lbecom e imbedded in it,soas to hold it with perfect security,

and in this way .a defective blale may be removed, and anew oneinserted,.at any time, bythe boats crew, without thc'aid of askilledmechanic.-

Claim;

'I claim as my invention-V The propeller herein described, consisting ofblades-.

of India rubber, taperingin thickness, bolted between metallic bars orplat-es, attached to a shaft, substanf tially as hereindescribed.

Y R. HUNTER. Witnesses:

W. M. AMPH, OGTAVIUs KNIGHT.

